Matt's Blog

Today’s little bit of “Now that I think about it, that makes sense…” wisdom: if your system happens to be a recursing nameserver, when running something to display open network connections, don’t let it resolve hostnames… Caching keeps it from becoming an infinite loop, but you will end up opening a new network connection for [...]

I noticed Wikipedia was extraordinarily slow. Instead of being normal and thinking, “Huh, I can’t reach Wikipedia,” I decided to investigate. One neat thing about Wikipedia is that it’s very open: not just in the sense than anyone can edit Wikipedia or that Mediawiki is open-source, but that you can view their Ganglia monitoring system [...]

I don’t put a lot of faith in DNSBLs, which are blacklists of spammer IPs. (They’re hosted as nameserver entries; you’d submit a DNS lookup for 4.3.2.1.example.com, where example.com was the DNSBL, to see if 1.2.3.4 was in the list; if it was, you’d get an “A” record of 127.0.0.2 (customary) back as a match.) [...]

Since I was curious… A graph of spamming IPs I’ve encountered in the past 14 days (1,075) by country (78 total). It’s only showing the top 11. (Excel’s decision.) Note that, as much as people love to blame China for spam (they are #1), the US is #9. (47 IPs, to China’s 139.) You could [...]

It looks like T-Mobile’s going to start selling a phone (made by HTC!) in about a month running Google’s Android. Engadget has more on the phone. What interests me more than anything is its openness: Palm has an SDK, and so do most of the other smartphone makers. But none are totally free, or actively [...]

McCain has decided he will have time for the debate after all. (In fact, CNN reports that McCain is bizarrely already claiming to have won the debate.) In addition to McCain, the KKK has announced it will be in attendance, too. This should be, err, interesting.

So I’m admittedly biased against McCain, but I couldn’t help but find his decision to suspend his campaign to be… Strange. For some reason (maybe it’s because it’s what we did in school for years?), I couldn’t help but view it as a strategic move. And in that case, it was brilliant. For a candidate [...]

I thought I’d share my latest discovery. Linux has two “random number generators” as pseudo-hardware devices (that is, they’re in /dev, but aren’t actual hardware, much like /dev/null.) They’re called /dev/random and /dev/urandom. I never knew, or even thought much about, the difference. /dev/random will “block” if it runs out of entropy. /dev/urandom is less [...]

I tweaked the policyd rules and my main.cf a bit more, so that my mailservers lets PolicyD do most of the examinations. The net effect was that Postfix itself (my mailserver, or MTA to be more accurate) stopped rejecting as many hosts, instead allowing PolicyD, a plugin I use to do some more advanced filtering, [...]

From the BBC today: Russian warships have set off for Venezuela for joint exercises unprecedented since the Cold War. To my elected officials: please, please, please don’t allow for Cold War II. I’ve for a long time perceived that increasingly large parts of the world hated us. And it’s easy to think, “So what if [...]